Re: 140gr Sierra-.270 win
Basic rule of life, lighter bullet = faster powder. If you're using the 4831 for the 140, you might step on down to a somewhat faster choice with the little 90 grainer. Might try the 4350 there, or even something just a tad faster. There's always 4320 and even 4064 in the IMR series, and any number of options in the same burning range among the various competitors out there.
Hope that helps!